Saturday, March 29, 2008

end of holiday.

My only mid-semester break for this semester is now almost over. One week seems a short time for me. How time flies and now my second rotation will start on this Monday.

My next rotation would be anaesthetic, dermatology, rheumatology and plastic surgery (Skin, Bone and Joints). There is a lot of anatomical stuff involved in this block. I don't know how many muscles, bone and ligaments that I should remember by the end of this rotation.

This reminds me of my last four weeks in Semester 3. The last four weeks were purely anatomy. Almost all the lectures were about muscles, bones and joints in upper and lower limb. If I'm not mistaken, there are about 20 muscles in the forearm and I used to remember a mnemonic to remember the name of those muscles. I need to find those mnemonics again and dig up my old lecture notes.

Anyway, I would like to bring up this quote again from my old post, Lost and Found.

Lost : Ability to enjoy life and time to spend with friends and family.
Found : Overwhelming sense of impending doom.
Last seen : Before entering medical school.

This sound right to me :D

heavy website

How fast your website can load? It is an important question whenever I design my blog layout. Not many people have fast internet connection and many people tend to discard any website that is slow to load.

There are several things that will slow down the loading time of websites. Having too many advertisements, images and Flash objects will hinder the loading time of any websites. Putting complicated JavaScript might cause internet browser such as Internet Explorer and Firefox to stall or crash.

One of the tools that I used to check my blog layout is Pingdom Tools. It gives detail analysis of what is being downloaded whenever someone is visiting this blog.

Here is the snapshot of the analysis. The full report is here.

The current layout for my blog at the moment is a bit heavy since it has few JavaScript and various small images. If I have time, I might redesign the entire layout to make it simpler than the current design.

Tuesday, March 25, 2008

Easter Break

I am in the middle of one week of Easter break. One week of holiday is a good time for me to do some revision. In fact, I need to revise my previous three rotations in the last semester. There are lot of stuff to be covered.

The coming exam is a major exam that contributes a lot of mark towards the final assessment of my 6 years course.

Unlike the pre-clinical exams which only involve answering multiple choice questions, essay and performing standard physical exam, this time, the exam would be a little bit different. One new component is to do long case presentation in front of a physician and a surgeon. You would be confronted with questions from them and you will never know what kind of questions you will be asked. This requires good and broad medical knowledge on common clinical conditions. Hopefully I will be able to remember the important facts when the exam comes which will be in less than 2 months.

Interpreting Electrocardiogram (ECG)

ECG is one of the popular medical machines shown on TV. It is usually shown whenever an actor/actress is dying and the sound of beep is associated with death. ECG illustrates the electrical activity of the heart and can indicate various heart diseases.

ECG contains various squiggles (waves) that are hard to interpret for any beginner. I was overwhelmed by ECG throughout my cardiorespiratory rotation and it took me a while to understand the basic of ECG. There are various heart diseases and hence various ECG patterns for each disease.

The target audience for this post is for any medical students who are starting to learn about ECG and thus, the rest of this post may contain various medical jargons.

There are 5 important waves in ECG. P wave represents atrial contraction, QRS complex represents ventricle depolarisation and T wave is associated with ventricle repolarization.

This is what an ECG printout looks like. It shows 12 leads and one rhythm strip usually from Lead II. ECG look at the heart from 12 different angles and each angle has different shape of waves. There are 6 limb leads (I, II, III, aVL, aVR and aVF) and 6 precordial leads (V1 to V6) and you should remember the names of each lead.

Image from ECG Library

Lead II, III and aVF are called inferior leads since they look at inferior surface of the heart. Lead I, aVL, V5 and V6 are lateral leads. Lead V1 to V4 are anterior leads.

Inferior leads are located at the bottom left hand corner of ECG printout and anterior leads are located in the middle. If you are able to remember this location, interpreting ECG will be easier and you might able to correlate any episodes of ischemic heart disease with the coronary arteries :).

One of my consultants came up with a good mnemonic for ECG. This mnemonic serves as a foundation and it will be a good starting point for any beginner with ECG.

Please remember that one small square in a standard ECG strip represents 0.04 s (40 ms) and one large square represents 0.2 s (200 ms).

Rate Rhythm Axis Hypertrophy Interval Morphology
  1. Rate
  2. To calculate the heart rate, we need to find the distance between one R wave and the subsequent R wave (RR interval). The formula for calculating the heart rate is:
    Heart rate = 300 / RR interval.
    In this formula, RR interval is the number of large squares. Therefore, if there are 5 large squares between one R wave to the subsequent R wave, the heart rate is 300/5 = 60 beats per minute (bpm). If RR interval is 3.5 large squares, heart rate is 300/3.5 = 86 bpm.

  3. Rhythm
  4. There are two main rhythms that we need to differentiate. The rhythms are either sinus rhythm (normal heart rhythm) or non-sinus rhythm. If there is normal P wave in ECG, this is most likely to be in sinus rhythm. If there is no P wave, it is more likely to be in non-sinus rhythm.

  5. Axis
  6. To determine heart axis, look for main wave deflections at Lead I and aVF. Positive deflection is defined when the height of R wave is greater than the S wave and negative deflection when the height of S wave is greater than R wave.
    Please refer to the diagram above. If the main wave deflection in Lead I is positive and lead aVF is negative, the heart axis is left axis deviation. If both leads are negative, the heart axis is not able to be determined.

    Please note that in the diagram above, positive for lead aVF is at the bottom instead of pointing up.

  7. Hypertrophy
  8. This will only cover about left ventricle hypertrophy. There are three ways to determine whether left ventricle hypertrophy exist.

    The first method is to calculate the height of S wave in V1 and R wave in V5. The second method is to use two different leads, S wave in V2 and R wave in V6. If the sum of both waves is greater than 7 large squares (35 small squares), the heart has left ventricle hypertrophy.

    The third method is to calculate the height of R wave in lead aVL. If the height of R wave is greater than 12 small squares, we can assume that the heart has left ventricle hypertrophy.

  9. Interval
  10. There are three main intervals that we are concerned for in ECG. The intervals are PR, QRS and QT. The normal range of PR interval is less than 1 large square (0.2s) and for QRS complex, is 3 small squares (0.12 s).

    In term of QT interval, we need to determine whether QT is prolonged or not. If QT interval is more than half of RR interval, QT is prolonged.

  11. Morphology
  12. There are various morphology that we need to know but as for a beginner, we can start with P wave.

    If P wave is 'tall, pointy, pulmonale', this indicate right atrial enlargement.

    If P wave is 'short, comfortable to sit on, mitrale', this indicate left atrial enlargement. Please refer to the diagram below.

A journey of a thousand miles begins with a single step and hopefully this will help you to make the first step in understanding ECG.

A good book that I highly recommends to learn more about ECG is 'The ECG Made Easy' by John R Hampton. There are various excellent website resources for ECG. Among them are ECG Learning Center, ECG library and ECG tutorial.

BMJ has good resources on ECG. Here are the topics under ABC of Clinical Electrocardiography.
If you would like to test your ECG skills, ECG Wave-Maven will be good for you :).

UPDATE 4 April 2008 : Add more web resources for ECG.

Saturday, March 15, 2008

The Heart

Sometimes it is difficult to explain to the patients about what is wrong with their heart. There are many structures in the heart that can be involved in any heart disease.

One of my consultants taught me one extremely useful analogy for the heart. Ask the patient to think the heart as a house. A house which is made of wall, doors, wiring and plumbing. Any of these structures can be affected in heart disease.

Wall of the house represent the muscular wall that surrounds the heart. It can be enlarged, thicken or rupture.

The doors represent the heart valve. It can be floppy, hardened or become invaded with germs. There are 4 main valves in the heart namely aortic, mitral, tricuspid and pulmonary valve. All of these valves can cause different types of murmur (sound that you can hear with a stethoscope).

Plumbing is referring to the blood vessels (coronary arteries) that supply oxygen to the heart muscle. The vessels can be blocked leading to reduction of blood supply to the heart muslces of which can cause heart attack.

Wiring reflects the electrical conduction of the heart. For heart to beat continuously, it depends on an intricate framework of electrical system throughout the whole heart muscles. If any of these wires being cut or short circuit, the heart will become completely haywire.

It is a good analogy of the heart :)

English is difficult

This can be found in many websites and I'm not sure who is the original author, but it is true. It might explains why English is so difficult to learn ;)

  1. The bandage was wound around the wound.
  2. The farm was used to produce produce.
  3. The dump was so full, that it had to refuse more refuse.
  4. We must polish the Polish furniture.
  5. He could lead, if he could get the lead out.
  6. The soldier decided to desert his dessert, in the desert.
  7. Since there is no time like the present, he thought it was time to present the present.
  8. I did not object to the object.
  9. There was a row among the oarsmen, about how to row.
  10. They were too close to the door to close it.
  11. Upon seeing the tear in the painting, I shed a tear.
  12. How can I intimate this, to my most intimate friend?
  13. It's time to wind down the wind farm.
  14. Most common people, live on the common common.
  15. I shed my clothes in the shed.
There is no egg in eggplant, nor ham in a hamburger, neither apple nor pine in a pine-apple. English muffins weren’t invented in England, nor French fries in France. Sweetmeats are candies while sweetbreads, which aren’t sweet, are meat.

We take English for granted, but if we explore its paradoxes, we find that quicksand can work slowly, boxing rings are square, and a guinea pig is neither from Guinea, nor is it a pig. Why it is that baker’s bake, but grocers don’t groce? If the plural of tooth is teeth. Why isn’t the plural of booth beeth?

One goose, 2 geese. So one moose, 2 meese? One index, 2 indices?

If teachers taught, why don’t preachers praught? If a vegetarian eats vegetables. What does a humanitarian eat?

In what language do people recite at a play and play at a recital? We ship by truck and send cargo by ship?

You have to marvel at the unique lunacy of a language, in which a house can burn up as it burns down, in which you fill in a form by filling it out, and in which an alarm goes off by going on. English was invented by people, not computers and it reflects the creativity of the human race (which, of course, isn’t a race at all).

That is why, when the stars are out, they are visible, but when the lights are out, they are invisible.

And finally, how about when you want to shut down your computer, you have to hit “START”!

Sunday, March 09, 2008

Tsunami of change in Malaysia

The result of the election is totally surprising. The people have spoken. Almost all the northern states (Kedah, Penang, Perak, Kelantan) and Selangor fall to the opposition parties. The biggest shock was the defeat of Samy Vellu at Sungai Siput. That is so close to my hometown, Kuala Kangsar.

Saturday, March 08, 2008

Interesting short movies

Somewhere Over The Rainbow - Israel Kamakawiwo Ole's version

Space Alone

I found this from Smashing Magazine - 25 Brilliant Animated Short Movies

Sunday, March 02, 2008

Clerking patient

Found this video from Malaysian Medical Resources. It was created by IMU medical students.

Hilarious :).

Saturday, March 01, 2008

Favourite websites

I have been asked by Sarah to list down 5 of my favourite links/websites that I frequently go to. Well, this will be a bit difficult since I have many favourite websites :).

Since this is the case, I might as well list down some of my favourite websites. I collect all the feeds from these websites in my Google Reader and hence the link to my Google Reader should be the first on the list, but don't think that is a valid link ;).

To understand my choice of favourite websites, you need to know that I have two totally different interests. One is related to the medicine since that is what I'm doing currently and another hobby of mine is associated with web design.

I read several websites to gain a broader perspective of what is happening around the world.
  1. New Strait Times Online. This is for news from Malaysia.
  2. Google News Australia. It collects news from major Australian newspaper. It is useful to know what is happening around Malaysia. At least you can use this info to talk with the patient when you are stuck in the middle of the interview :) and some issues in Australia can affect you directly. It is important to know local situations whenever you stay in overseas.
  3. BBC News. This informs me of global news and can be quite useful for comparison study. The same event can be perceived differently depending on the reporter's background.
  1. emedicine. I use this website to learn about any diseases although not all diseases are described in the website. I subscribe to Emedicine Clinical Case which regularly gives you a a brief description on patient and ask you to diagnose the condition. It is a good test to refresh my medical knowledge :)
  2. Access Medicine. This requires subscription and shows online version of many books. My university subscribes to this website and it is available to Melbourne University students. This is another alternative whenever I'm studying for medicine.
  3. Up To Date. Another web that requires subscription. Apparently, the hospital I'm attached to, subscribes to UpToDate and it is available for the staff and medical students. This contains the latest info on any diseases around the world. I could even find info on rare disease. It is always being updated for every 5-6 months.
  4. Merck Manuals - Online Medical Dictionary. This website does not requires any subscription. It is another excellent source for medical information on various disorders.
Web Design
  1. Smashing Magazine. This is an extremely useful website and highlights important article and websites for web designer around the world. Their motto is "we smash you with the information that will make your life easier. Really."
  2. Ars Technica. It contains news related to the information technology be it Google, Apple, latest gadgets, internet, web browsers or even web standard.
  3. Veerle. This is a personal blog of a famous web designer. I learned a lot from this blog.
As per instruction, I need to tag 5 peoples but I don't think I would like to do that. Anyway, hopefully the links above will be useful to you.

UPDATE 5 APRIL 2008: Add Merck Manual and edited the post.